Wireless communications have shown a profound effect on society today. In only a few short years, cellular telephones have attracted millions of subscribers in the United States, Europe, and Asia. While this dramatic development is just the start of the telecommunications revolution, it is also just the start of a revolution in piracy and fraudulent use of cellular telephones.
The typical prior art cellular telephone uses nonvolatile writeable memory to store either data, or code, or both. Such nonvolatile writeable memories include Electrically Erasable Programmable Read-Only Memories (EEPROMs) and flash Erasable and Electrically Programmable Read-Only Memories (flash EPROMs, or flash memories). The flash memory of the typical prior art cellular telephone comprises an equipment serial number (ESN) or international mobile equipment identifier (IMEI). When the cellular telephone is operated, the ESN or IMEI is broadcasted to allow the cellular service provider to identify the user as a legitimate subscriber in order to provide the user with access to the cellular network and to bill the user for the access to the network. Fraudulent cloning occurs when the ESN or IMEI is obtained by fraudulent means and reprogrammed into another cellular telephone in an effort to avoid paying for cellular telephone service. Furthermore, embedded systems face a similar problem whereby application code is read from a flash memory in an effort to reverse engineer the product.
Piracy or fraud occurs in the typical prior art analog cellular phone when the analog signal transmitted from the cellular telephone is intercepted and decoded to provide the cellular pirate with the ESN or IMEI of the broadcasting user. The cellular pirate then uses the acquired ESN or IMEI by programming it into other analog cellular telephones. When these fraudulently cloned cellular telephones are used, the airtime is billed against the pirated ESN or IMEI.
Another opportunity for cellular piracy arises when cellular telephone hardware is subsidized by different service providers abroad. For example, a service provider in England may provide a cellular telephone to a subscriber at a cost of $200 with a two year service subscription. In contrast, a service provider in Finland may provide a cellular telephone to a subscriber at a cost of $1,000 with a two month service subscription. Therefore, the cellular telephone has a significantly different value depending on the country in which it is used. The fraud opportunity that arises is for a cellular pirate to purchase cellular telephones in England at a cost of $200 and take them to Finland where they are sold for an amount less than $1,000 but significantly more than the $200 purchase price.
As there is not a standard hardware security protection scheme, each OEM must implement their own fraud prevention scheme. Some OEMs of cellular telephones make no effort to prevent cellular piracy. One fraud-prevention technique used by some OEMs in a typical prior art cellular telephone is to bury a unique code in the cellular telephone system software memory space. The system software knows the address of the code and uses this code to access the system software. The problem with this technique is that it is easily defeated by erasing the entire memory and installing new system software and reprogramming the same identification that was originally in place.
Another problem in the typical prior art Global System for Mobile Communications (GSM) cellular telephone is in the fraudulent use of the subscriber identification module (SIM) card, or smart card. The SIM card, the size of a credit card, slots into the cellular telephones allowing their users to make or receive calls while abroad but be billed when they get back home. While the SIM cards are designed for use with GSM cellular telephones, there has been consideration of allowing the SIM cards to be used with non-GSM phones such as card-operated public pay phones. However, fears that fraudulent abuse of the SIM card may be too difficult to prevent are placing ever increasing restrictions on its usefulness.
The GSM smart card carries the information required for users to make calls on GSM networks other than the one to which they subscribe. This is especially useful when traveling abroad, theoretically allowing users to make or receive calls almost no matter where they travel throughout Europe and increasingly also outside of Europe. However, fraud and the apparent inability of network operators to deal with it has meant that an increasing number of service providers, the group in the middle between the operators and mobile phone users, are now deliberately limiting the usefulness of the GSM SIM card. These limitations include limiting the SIM card to functioning only with the phone with which it was provided, a limitation that virtually eliminates the initial purpose of the smart card. Furthermore, some service providers, as a result of cellular telephone piracy, have proposed eliminating the SIM cards altogether, the argument being that it introduces a new level of complexity which criminals can exploit.
As a result of substantial losses incurred by foreign service network operators, a number of foreign service providers in a number of foreign countries are now disabling the GSM SIM cards from being allowed to be used while abroad. From now on subscribers to networks through those service providers will have to leave large deposits if they want to use their phones while abroad. Furthermore, some foreign service providers have now ceased all international roaming.